Even if you remove the port manually and save the entry, you will see the port is added back in. If we cannot manually override an entry like this then why leave it as a textfield and not as a non-editable field or plain text?

The "443" port is not necessary because 99.99% of devices today (if not ALL) know how to deal with HTTPS URLs. It just seems like an leftover forgotten from an earlier workaround feature.